there are no threads. so the error is pretty weird. this is stack trace:

from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/sqlite3-1.3.7/lib/sqlite3/statement.rb:108:in `block in each' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/sqlite3-1.3.7/lib/sqlite3/statement.rb:107:in `loop' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/sqlite3-1.3.7/lib/sqlite3/statement.rb:107:in `each' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/sqlite3-1.3.7/lib/sqlite3/database.rb:149:in `map' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/sqlite3-1.3.7/lib/sqlite3/database.rb:149:in `block in execute' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/sqlite3-1.3.7/lib/sqlite3/database.rb:95:in `prepare' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/sqlite3-1.3.7/lib/sqlite3/database.rb:134:in `execute' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/sqlite3-1.3.7/lib/sqlite3/database.rb:506:in `commit' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-4.0.0/lib/active_record/connection_adapters/sqlite3_adapter.rb:368:in `block in commit_db_transaction' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract_adapter.rb:425:in `block in log' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/activesupport-4.0.0/lib/active_support/notifications/instrumenter.rb:20:in `instrument' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract_adapter.rb:420:in `log' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-4.0.0/lib/active_record/connection_adapters/sqlite3_adapter.rb:368:in `commit_db_transaction' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/transaction.rb:176:in `perform_commit' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/transaction.rb:116:in `commit' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/database_statements.rb:236:in `commit_transaction' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/database_statements.rb:216:in `within_new_transaction' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/database_statements.rb:202:in `transaction' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-4.0.0/lib/active_record/transactions.rb:209:in `transaction' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-4.0.0/lib/active_record/transactions.rb:323:in `with_transaction_returning_status' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-4.0.0/lib/active_record/transactions.rb:270:in `block in save' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-4.0.0/lib/active_record/transactions.rb:281:in `rollback_active_record_state!' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-4.0.0/lib/active_record/transactions.rb:269:in `save' from /home/attilio/Dropbox/Ruby/Ants web/ar_stuff.rb:268:in `save' from maintenance.rb:26:in `ar_get_word_id' from maintenance.rb:15:in `rescue in get_word_id' from maintenance.rb:9:in `get_word_id' from maintenance.rb:46:in `block (2 levels) in <main>' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/sqlite3-1.3.7/lib/sqlite3/database.rb:142:in `block (2 levels) in execute' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/sqlite3-1.3.7/lib/sqlite3/statement.rb:110:in `block in each' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/sqlite3-1.3.7/lib/sqlite3/statement.rb:107:in `loop' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/sqlite3-1.3.7/lib/sqlite3/statement.rb:107:in `each' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/sqlite3-1.3.7/lib/sqlite3/database.rb:140:in `block in execute' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/sqlite3-1.3.7/lib/sqlite3/database.rb:95:in `prepare' from /home/attilio/.rvm/gems/ruby-2.0.0-p195/gems/sqlite3-1.3.7/lib/sqlite3/database.rb:134:in `execute' from maintenance.rb:42:in `block in <main>' from maintenance.rb:41:in `catch' from maintenance.rb:41:in `<main>'